1. Field of the Invention
This invention relates in general to the field of spark plugs for internal combustion engines, and in particular, to a method of injecting air into the combustion cylinder in order to effect a more efficient operation of the engine.
2. Prior Art
In the operation of internal combustion engines, one significant problem is the inability to effect a complete burning of the air-fuel mixture delivered by the carburetor or other types of fuel injection systems to the combustion cylinder. It is known that when a vacuum-balancing quantity of any combustion promoting vapor, such as oxygen or air, is introduced into the combustion chamber prior to the ignition of the air-fuel mixture, a reduction or complete elimination of the need for the piston to act against the progressive vacuum in the cylinder results. This lessening of the amount of energy expended by the piston as a result of the vapor injection has at least two positive advantages. Firstly, there is an increase in gas mileage since effective horsepower is increased. Secondly, a more complete combustion of the air-fuel mixture results and the emission of what is commonly called smoke or soot (i.e. unburned hydrocarbons) during the final upstroke of the engine is decreased, producing a cleaner less polluting exhaust. Other advantages can also arise if the engine is known to burn oil or is required to run on a high octane fuel. In the former case the oil deposits in the engine will be significantly lessened whereas in the latter a lower grade of fuel may be substituted.
The problem heretofore with injecting a metered amount of combustion promoting vapor, such as external air, into the combustion chamber during compression is that regardless of the type of injecting device used, the backpressure on the air inlet mechanism produced during the first upstroke of the engine is so great that there is a tendency for the mechanism to eventually break down and release excessive amounts of air or air-fuel mixture. It is known, in the prior art, that by providing an auxiliary chamber into which a part of the compression pressure may be permitted to escape, the backpressure on the air-inlet means of the injector is significantly reduced. However, because the compression pressures are so great, as much as six to eight times the volume of the air-fuel mixture, this provision has not satisfactorily addressed the problem. It is also known in the prior art, that an air inlet means that is responsive to the high pressures and high temperatures produced during compression, such as a ball valve mechanism, results in a lessening of backpressure. This method of injection has also proved unsatisfactory since the compression pressures and temperatures are so great.
Thus, although the prior art appears to have been cognizant of some of the problems associated with air-injection systems, no device heretofore has satisfactorily solved the problem of reducing backpressure in the system to the extent that this invention does.
In a distinct departure from the prior art, this invention teaches that by uniquely positioning an auxiliary pressure reducing chamber in association with an enclosed valve chamber housing a pressure absorbing valve inlet and outlet means, backpressure in the air-injecting device may be significantly reduced resulting in an increase in the useful life of the device and a consequent increase in the efficiency of operation.
This invention also teaches that by strategically locating an air inlet and outlet tube in a spark plug wherein such tube is also part of the positive electrode, both the positive and negative electrodes may be effectively cleaned and cooled as a result of the air-injection process and consequently be rendered more effective conductors of ignition spark. Although other air-injection systems might similarly provide a cooling and cleaning means for the electrodes of a spark plug, it is the unique internal configuration taught by this invention which makes such a process most effective.